package com.wc.AlgoOJ_homework.aloj练习赛.A_强哥归巢;

import java.util.Scanner;

/**
 * @Author congge
 * @Date 2024/5/8 20:23
 * @description http://43.138.190.70:8888/p/GDCPC1
 */
public class Main {
    static Scanner sc = new Scanner(System.in);
    static int n;

    /**
     * 思路，一路莽，超过了超过的数就让前面的数停下来步动就好了
     */
    public static void main(String[] args) {
        n = sc.nextInt();
        int s = 0;
        int res = 0;
        while (s < n){
            s += ++res;
        }
        System.out.println(res);
    }
}

